Apoptosis

What is apoptosis and how does it differ from necrosis?

• Apoptosis is programmed cell death; necrosis is uncontrolled cell death due to injury.

• Apoptosis is a reversible process; necrosis is always permanent.

• Apoptosis occurs only in plants; necrosis occurs in animals.

• Apoptosis is a type of inflammation; necrosis is a form of healing.

Answer explanation

Apoptosis is a controlled, programmed process of cell death essential for development and homeostasis, while necrosis is an uncontrolled process resulting from injury or disease, leading to inflammation and damage to surrounding tissues.

What are the characteristic morphologic features of cells undergoing apoptosis?

• Characteristic morphologic features of cells undergoing apoptosis include cell shrinkage, chromatin condensation, nuclear fragmentation, and formation of apoptotic bodies.

• Cell swelling and lysis

• Formation of large, multinucleated cells

• Increased cell size and organelle proliferation

Answer explanation

The correct choice describes apoptosis features: cell shrinkage, chromatin condensation, nuclear fragmentation, and apoptotic bodies. Other options describe processes like necrosis or cell proliferation, which are not characteristic of apoptosis.

How does apoptosis contribute to tissue regeneration?

• Apoptosis contributes to tissue regeneration by removing damaged cells and facilitating the growth of new, healthy cells.

• Apoptosis prevents tissue regeneration by promoting cell death.

• Apoptosis has no effect on tissue regeneration processes.

• Apoptosis leads to the accumulation of damaged cells, hindering regeneration.

Answer explanation

Apoptosis plays a crucial role in tissue regeneration by eliminating damaged cells, which allows for the proliferation of new, healthy cells. This process ensures that the tissue can heal and regenerate effectively.

What happens to the chromatin during the process of apoptosis?

• Chromatin condenses and fragments.

• Chromatin expands and unwinds.

• Chromatin remains unchanged.

• Chromatin dissolves completely.

Answer explanation

During apoptosis, chromatin undergoes condensation and fragmentation, which is a key feature of the process. This change is crucial for the orderly dismantling of the cell.

Describe the process by which apoptotic bodies are formed.

• Apoptotic bodies result from the process of necrosis and inflammation.

• Apoptotic bodies are formed through cell shrinkage, membrane blebbing, and fragmentation during apoptosis.

• Apoptotic bodies are created by the fusion of healthy cells.

• Apoptotic bodies are formed through cell division and replication.

Answer explanation

Apoptotic bodies are formed during apoptosis, characterized by cell shrinkage, membrane blebbing, and fragmentation, which distinguishes this process from necrosis and inflammation.

What role do macrophages play in the apoptosis process?

• Macrophages prevent the clearance of apoptotic cells.

• Macrophages are primarily involved in the production of antibodies.

• Macrophages help clear apoptotic cells and modulate the immune response.

• Macrophages induce apoptosis in healthy cells.

Answer explanation

Macrophages play a crucial role in the apoptosis process by helping to clear apoptotic cells, which prevents inflammation and promotes tissue homeostasis. They also modulate the immune response, ensuring a balanced reaction.

Why is the integrity of the plasma membrane important during apoptosis?

• The integrity of the plasma membrane is irrelevant to the process of apoptosis.

• The integrity of the plasma membrane prevents the release of harmful substances and ensures proper clearance of apoptotic cells.

• The plasma membrane allows all substances to enter the cell during apoptosis.

• The plasma membrane's breakdown is necessary for cell survival during apoptosis.

Answer explanation

The integrity of the plasma membrane is crucial during apoptosis as it prevents the release of harmful substances into the surrounding tissue and facilitates the proper clearance of apoptotic cells by phagocytes.

How does apoptosis prevent inflammation in surrounding tissues?

• Apoptosis promotes the proliferation of immune cells.

• Apoptosis causes cell swelling, leading to tissue damage.

• Apoptosis triggers inflammation by releasing cytokines.

• Apoptosis prevents inflammation by eliminating cells in a controlled manner, allowing phagocytes to clear apoptotic bodies without releasing inflammatory signals.

Answer explanation

Apoptosis prevents inflammation by eliminating cells in a controlled manner. This allows phagocytes to efficiently clear apoptotic bodies without triggering the release of inflammatory signals, thus minimizing tissue damage.